Lack, Loss, and Decreased Appetite (Dysrexia, Anorexia, and Hyporexia) in Dogs

Published on
Last updated on
4 min read

Key takeaways

Decreased appetite is common in dogs and occurs in association with a wide variety of illnesses and injuries.

  • Appetite changes range from a slight decrease, where a dog is willing to eat treats, to complete refusal to eat
  • Dogs who won’t eat anything at all for more than two or three days require prompt medical attention
  • Complete appetite loss accompanied with other serious symptoms like refusing to drink, weakness, or pale gums indicates an emergency
  • Common diagnostic tests include physical examination, blood work, urinalysis, fecal analysis, and diagnostic imaging
  • Treatment options vary widely depending on the underlying cause
  • The prognosis for appetite loss is also highly variable, with underlying conditions ranging in severity from temporary and self-limiting to life threatening
Are you concerned?

Connect with a vet to get more information about your pet’s health.

Book an online vet

A closer look: Lack, Loss, and Decreased Appetite (Dysrexia, Anorexia, and Hyporexia) in Dogs

Appetite loss in dogs is a common occurrence and is associated with a variety of underlying conditions, some of which are mild and some that are severe.

Decreased appetite can be differentiated from picky eating when it is severe enough or lasts long enough to lead to weight loss. Unexplained weight loss in dogs warrants prompt veterinary attention.

Prolonged appetite loss (greater than 72 hours), or when accompanied by vomiting or diarrhea, also warrants prompt veterinary attention.

Appetite loss accompanied by other serious symptoms like difficulty breathing, collapse, or pale gums is an emergency.

Medical terms for variations in appetite loss include:

Anorexia: a complete lack of appetite and food intake. Note: anorexia in animals refers only to the symptomatic presentation of not eating, which is not to be confused with the eating disorder Anorexia Nervosa in humans.

Hyporexia: diminished appetite or eating less

Dysrexia: a disruption in appetite. This is a common occurrence in dogs and the majority of dogs exhibit some symptom of diminished appetite at some point in their lifetime.

Connect with a vet to get more information

With DVM, ICH certifications and great reviews by pet parents like you for this symptom

Possible causes

Appetite loss and decreased appetite have multiple causes and do not always indicate a medical condition.

In addition to medical or physiological causes, environmental factors that often cause disruption to normal appetite include dietary change to unfamiliar food or food that is spoiled, and stress (e.g.boarding, new home, new pets, new family members).

Risk factors

Loss of appetite varies in duration and severity. A simple change in diet can lead to temporary, behavior-associated refusal to eat. Appetite loss associated with an underlying medical condition is often accompanied by additional symptoms such as vomiting or diarrhea. Since the causes of appetite changes are numerous, all dogs are at some risk of disruption to appetite.

Testing and diagnosis

Diagnostic tools to investigate appetite disruption include

  • Blood work
  • Diagnostic imaging
  • Fecal analysis
  • Physical examination

Specific treatment varies widely depending on the underlying cause of appetite loss. Symptomatic therapy often includes IV fluids, appetite stimulants, anti-nausea medication, antibiotics, and highly palatable dietary therapy.

Similar symptoms

Picky eating is easy to mistake for decreased appetite. True, sustained appetite disruption is distinct from picky eating, as picky eaters usually do not lose weight in their efforts to demand palatable food.

Associated symptoms

Any condition that results in oral pain, like a tooth abscess, may be accompanied by food aversion. Characteristics of food aversion include, disinterest in food, walking away or refusing food, sniffing or looking at food but no interest in eating, turning head and nose away or moving away from the food bowl.


Jennifer Coates, DVM - Writing for PetMD
Audrey Cook BVM&S, MSc VetEd, MRCVS, DACVIM (SAIM), DECVIM-CA, DABVP (Feline) - Writing for Today's Veterinary Practice
Wendy Brooks, DVM, DABVP - Writing for Veterinary Partner
Dr Audrey Cook, DACVIM, MRCVS - Writing for Today’s Veterinary Practice

Our editorial committee

Our medical review team is responsible for validating and maintaining the quality of our medical information.